Study on the Establishment of a Rapid Propagation System for Succulent Plant Haworthia heidelbergensis

This study took the inflorescence and leaves of the succulent plant Haworthia heidelbergensis as explants, and explored the effects of different mediums with different hormone ratios on the rapid propagation of Haworthia heidelbergensis. The results showed that the optimal medium component for inflorescence callus induction was MS (Murashige and Skoog)+2.0 mg/L 6-BA+1.0 mg/L 2,4-D+0.2 mg/L NAA, the callus induction rate was 90%; the optimal medium component for leaf callus induction was MS+0.5 mg/L 6-BA+2.0 mg/L KT+0.3 mg/L NAA; the optimal medium for callus differentiation was MS+1.0 mg/L 6-BA+2.0 mg/L KT+0.3 mg/L NAA, the clump bud differentiation rate was 50%; the optimal medium for clump bud proliferation was MS+0.5 mg/L 6-BA+1.0 mg/L KT+0.05 mg/L NAA, the proliferation rate was 600%; the best medium for rooting was 1/2 MS+ 0.2 mg/L NAA+0.3 g/L AC. In conclusion, this study selected the explants and culture mediums, established an aseptic propagation system and provided a reference for the in vitro culture and rapid propagation of Haworthia heidelbergensis.

CW-OSL, LM-OSL and TL dating of bricks from Karakorum, Mongolia: Insights from TL spectra

In this study, we present results of luminescence dating using CW-OSL, LM-OSL and TL on heated quartz from the archaeological and historical site in Karakorum – the ancient capital of Mongolia, to test their convergence with the age control in the form of the Karakorum inscription 1346. The TL spectra conducted on quartz from red and grey coloured bricks appeared to be characteristic of the technological origin. Quartz TL from red bricks showed a UV emission band at ~360 nm and a strong fast OSL component dominated signal. In contrast, blue emission detected in the TL spectra of grey coloured bricks, resulting possibly in the medium component dominated OSL signal. Finally, OSL and TL results gave dates from 1180±70 AD to 1360±70 consistent with the expected ages.

Synthesis and Physicochemical Properties of Exopolysaccharides Produced by Lactic Acid Bacteria Leuconostoc mesenteroides Cultured in Lactose- and Sucrose-Containing Medium

The dynamics of Leuconostoc mesenteroides bacteria growth and synthesis of exoplysaccharides when cultured on a medium containing whey and sucrose has been investigated. It was shown that exopolysaccharides were produced during the culture growth and the addition of sucrose increased in the productivity of those compounds without affecting their composition. Using the dynamic and static methods of light scattering, it was shown that sucrose as a medium component modified physicochemical properties of exopolysaccharides changing their structural and thermodynamic characteristics in aqueous medium, which affected their functional activity and determined the way of their most efficient use. kefir fungi, lactic acid bacteria, physicochemical properties of exopolysaccharides.